Hey Peter,
Welcome to the forums and the world's greatest sport, surfski!
If you're competent in the X Par you can probably catch on the the V10S pretty fast. The key is just building up the wave progressively and pushing yourself into sliiiightly larger conditions than you feel 100% comfortable in. a feeling of like 90% confidence pushes your skill forward without excessive risk (to me at least, everyone has their own limit for pushing themselves)
Since you're in cooler water and summer is here a drysuit will become uncomfortable pretty fast. to gain initial comfort in the boat, maybe you could take it to a lake or river and chase boat wakes around without the suit. Boat wakes are quite good stability practice because they are such short interval and steep. If you can manage a large boat wake on the ski, you're probably ready to head to the ocean on a small/medium day.
A 3/2 or 4/3 wetsuit would probably be more comfortable for summer paddling if its in your budget at all.
For comparison,I paddled ski on flat water lakes and rivers for 1.5 years before moving to the coast and going into the ocean. I would have paddled on the ocean day 1 if i lived near it at the time. I think the key to gaining skill, having fun, and not killing yourself is understanding the conditions and your limitations well enough to make an informed risk assessment. the cold Maine water is already a higher risk factor, so you should consider proper immersion gear (sounds like you're aware and prepared here), wind direction (on shore is always best) tide direction (incoming is probably better than outgoing safety wise), signaling devices (VHF radio, phone, lights, whistles, mirror etc), and paddling with a group.
Another thing that will help a lot is if you can get on the water, even for a short paddle, like 3+ times a week. Stability and confidence go up quickly when you're in the boat a lot. If you're only a weekend paddler, things go much slower as you're trying to develop unconscious muscle memory and repetition is key for that.
Practice remounting every paddle until you can do it easily and even then do it regularly. Practice it in waves. At first, maybe go to a lake, wait for a big boat wake to pass and try remounting when the waves are hitting you. This way you can practice remounting in waves but if you fail the set will pass and you can get back on.
Assuming you take proper precautions and are motivated I think you could safely be paddling in 3 footers later this summer. Just choose your conditions appropriately and always have a bailout plan. Find a group as well. NECKRA has a good presence all over new england. Wesley and some of his friends paddle regularly out of RI, and there's a good SS crowd that does the Blackburn and others. Plenty of people to learn from if you're motivated.
Anyways, keep at it, you'll have a blast!